The axial clearance under different bearing gas supply pressures can be measured through rotor static test. The effects of the axial clearance on the stability of high-speed dual-turbine rotor of generator can be analyzed by vibration test and analysis methods

including three-dimensional spectrum

axis center tracks and frequency spectrum characteristics. Results showed that the gas film half-speed whirl and gas film whip appeared during run-up when the left and right sides of the axial clearance were not equal. When the axial clearance of the left and right ends of the rotor was equal

the gas film half-speed whirl and gas film whip disappeared

which could enhance the stability of gas bearing rotor system.